THE GEOPHYSICAL RESEARCH AT SYNTAGMA SQUARE - ATHENS RELATES GEOLOGICAL FINDINGS TO ANCIENT TEXTS

• M. G. Papaioannou, St. P. Papamarinopoulos (Laboratory of Geophysics, Section of applied Geology and Geophysics, Department of Geology, University of Patras, 261 10 Patras, Greece)

The Geophysical research that took place between 1992-93 at the center of the city of Athens and more precisely at the area of Syntagma, brought to light new archaeological and geological evidence. The use of geophysical methods in urban environment has been "revolutionary", with many problems but also significant results. This research began during the construction of the Athens Metro and initially aimed at programming the following steps of the construction of Syntagma Station so as to make the works easier. But, very important geological and archaeological evidence came up, as the investigations progressed. The utilization of georadar of several frequencies led to the impression of the geological and archaeological reality at various depths, becoming a helpful tool in the development of the works. The discovery of the subterranean river Eridanos and the mapping of its course was one of the first evidence that turned the interest to ancient texts and the relation through them, of known and unknown buildings to the course of the river. Many of the human activities that came to light after the excavations on Amalias Avenue, are directly related to the existence of the river in the vicinity. A second and by first looks purely geological evidence, was the discovery of a syncline at the Syntagma Square area. The geology combined to the existence of the river and this syncline feature, can be related to "cosmogonist situations" and adverse phenomena like foods and earthquakes described at Plato's texts and in particular at "Timaeos and Critias". Several other writers mention the river Eridanos and relate it to many known and unknown features of the ancient city of Athens. Drillings and excavations at the area come to verify the geophysical discoveries, proving once again the effectiveness of geophysical methodology in underground surveys even when it comes to urban environment.